This application is a national stage filing of international application PCT/KR99/00465, filed Aug. 19, 1999 which claims priority to Korean Application Number 1998/33637 filed Aug. 19, 1998. Priority is claimed to both of these prior applications.
The present invention relates to a high voltage pulse generator using a non-linear capacitor or, more particularly, to a device using a voltage amplification effect of a non-linear capacitor, which can generate a pulse of a short pulse width at high voltage.
In many application fields of pulse power, a short high-voltage pulse having a high repetition rate is needed. A discharge-type switch is usually used in producing a short high-voltage pulse. A high-voltage pulse generating circuit using a conventional discharge-type switch is shown in FIG. 8. However, the conventional discharge-type switch has a short life span and low reliability as well as a low repetition rate. In addition, the circuit has a shortcoming of being a large size because it uses a pulse transformer and a self-saturating switch.
In contrast, a semiconductor switching component has a long life span with high reliability. However, its operational voltage range and switching time are not suitable for directly driving a pulsed power system, which requires voltage amplification (transformation) and pulse compression methods. Unfortunately, a pulse transformer and a magnetic pulse compressor have a low energy efficiency and a large size.
The present invention is, therefore, directed to providing a high-voltage pulse generating device having high efficiency with small size, using a semiconductor switching component.
The present invention also seeks to provide a high voltage pulse generating device using a semiconductor switching device with a long life span, but which does not use a pulse transformer or a magnetic pulse compressor as required by conventional circuits of the prior art.
The present invention uses the voltage amplification effect of a non-linear capacitor, which was observed during the research of BaTiO3 ceramic capacitors by the inventors. A ceramic capacitor has a characteristic that its capacitance is generally decreased at a voltage higher than the rated value. Because reduction in capacitance is analogous to opening a switch, a non-linear capacitor may be used for pulse generation in an inductive storage system. The present invention utilizes this non-linear characteristic of a capacitor.
A high-voltage pulse generating device according to the present invention comprises a semiconductor switch connected to one output terminal of a DC power supply or rectification circuit, a primary inductor connected between an output of said semiconductor switch and the other output terminal of said rectification circuit, a diode in which the cathode thereof is connected to the output of said semiconductor switch, a capacitor connected between an anode of said diode and the other output terminal of said rectification circuit, a secondary inductor in which one terminal thereof is connected to the anode of said diode, a non-linear capacitor connected between the other terminal of said secondary inductor and the other output terminal of said rectification circuit, and a load connected in parallel across two terminals of said non-linear capacitor.